This invention relates to an electrically actuated overhead garage door opener assembly and more particularly, to improvements therein which provide greatly increased security for the garage door in its closed position. Furthermore, the improvements of the present invention include the use of a unique electrically actuated solenoid construction which is greatly simplified over the prior constructions while providing a more positive and dependable operational function so as to be capable of manufacturing and use at a reduced overall cost.
Electrically actuated overhead garage door opener assemblies have been in use for a relatively long period of time functional for automatically opening and closing garage doors through control by either an interior control switch or remote control means normally carried in the automobile making use of the garage. Furthermore, it is a well known fact and quite disturbing to the average citizen that crime has been increasing rapidly over the past decade, particularly including unauthorized residential entry with resulting burglary and sometimes even more serious personal crimes. As related to the present subject matter, many of these attempts at unauthorized entry and particularly the unauthorized entry of residences have been directed at unauthorized entry of residences through overhead garage doors and in many cases where the entry into the garage provides directly connected and ready entry into the residential living quarters. Unfortunately, an alarming number of these unauthorized entry attempts have been successful.
Considering a specific example, these automatic garage door openers are commonly installed for opening and closing garage doors of the solid or single-piece assembly type wherein the garage door is pivotally mounted movable from closed position pivotally upwardly and rearwardly to an overhead, nearly horizontal position. With this type of garage door installation, two basic forms of automatic garage door opener assemblies are used, one of the friction engagement form and one of the rack and pinion form. With the friction engagement form, the electrically actuated garage door opener having an upper extremity of the door connected thereto travels rearwardly and forwardly along a nearly horizontal guide track with resilient rollers of the opener frictionally engaged with the guide track to supply the relative motion therebetween. In the rack and pinion form, the relative motion is supplied by a rotatable pinion of the opener moving along a rack of the guide track.
Considering the friction engagement form of automatic garage door opener installed with the pivotal solid assembly garage door, despite the fact that the relatively strong frictional engagement of the door opener maintains the garage door in a moderately secure closed position when in the non-actuated condition, it is still possible, if sufficient forces are applied near the lower edges of the door, to force the door toward open position. In other words, sufficient force is applied toward pivotally moving the door from closed toward opened position that the normal frictional bond between the opener and guide track is overcome a sufficient distance along the guide track to create an access opening beneath the door lower edge. Where the opener is of the rack and pinion form, frequently similar sufficient forces on the door will cause the pinion of the opener to "back" along the rack of the guide track resulting in a similar access opening. Even where the rack and pinion form is constructed to completely prevent any non-actuated relative movement between the pinion and rack, it still has been found possible to apply a sufficient force to a lower corner of the garage door which causes the same to flex or break and result in an unauthorized access opening.